Passivating the grain boundaries is completely very crucial in the enhancement of the performance of halide perovskite solar cells (PSCs). Here, a novel organolead halide perovskite (CH3NH3PbI3) was synthesized using solution processes-based method to sensitize 1D titanium dioxide (TiO2) and reduced graphene oxide (RGO) nanoparticles for all-solid-state halide perovskite solar cells. TiO2 and RGO were synthesized via sol-gel and Hummers’ methods, respectively, and incorporated at the electron transport layer (ETL) in planar PSCs. Additionally, MnO2 was prepared by chemical method, and used to enhance graphite counter electrode. ITO/RGO/TiO2/CH3NH3PbI3/Gr and ITO/RGO/TiO2/CH3NH3PbI3/Gr-MnO2 planar PSCs were fabricated via spin coating method. ITO/RGO/TiO2/CH3NH3PbI3/Gr-MnO2 film achieved a power conversion efficiency (PCE) of 10.79%, short circuit current (Jsc) of 19.0 mAcm-2 and fill factor (FF) of 51.53% compared to PCE of 8.64%, Jsc of 16.25 mAcm-2 and FF of 47.48% achieved for ITO/RGO/TiO2/CH3NH3PbI3/Gr film. The enhancement value of 22.85% was achieved from J-V curves after exposing the ITO/RGO/TiO2/CH3NH3PbI3/Gr and ITO/RGO/TiO2/CH3NH3PbI3/Gr-MnO2 films to Keithley 2400 sourcemeter (Keithley Instrument Inc.) under AM 1.5G (100 mWcm-2) (Newport) solar illumination in order to test their photovoltaic performance. This study shows that MnO2 nanoparticle has a proven capability to improve the photovoltaic performance of PSCs.